Lehr construction



Sept. 6, 1938. 1 F. GREENE LEHR CONSTRUCTION Filed Oct. 3l, 1935 3She'etS-Sheet 1 ATTORNEY Sept. 6, 1938; J, F. GREENE 2,129,057

LEHR CONSTRUCTXON Filed oct. 31. 1935 5 sheets-sheet 2 NVENTOR J5 SEA/ff/MINE ATTORNEY Sept. 6, 1938. J. F. GREENE I 2,129,057

LEHR CONSTRUCTION Filed oct. 51, 1935 s sheets-sheet 3 ATTORNEY PatentedSept. S, 1938 UNITED STATES LEHR CONSTRUCTION Joseph F. Greene,Vineland, N. J., assignor to Kimble Glass Company, Vineland, N. J., acorporation of Illinois Application October 31, 1935, Serial No. 47,619

4Claims.

This invention relates generally to heating furnaces and has particularreference to a furnace or lehr adapted for the annealing or heattreatlng of glass and similar articles.

One of the primary objects of this invention is to provide an annealingfurnace or lehr of the above mentioned character which will includemeans for efliciently eecting a precise control and distribution of heatwithin the annealing chamber.

More particularly the invention contemplates the provision of means forsimplifying the control of the heat distribution within the annealingchamber to the end that the ware being treated may be brought up to thetemperatures desired without the use of a complicated system oftemperature control mechanisms.

Numerous other objects and advantages of the invention will become moreapparent as the following description proceeds particularly whenreference is had to the accompanying drawings wherein Fig. l is asemi-diagrammatic top plan view of a lehr constructed in accordance withthe teachings of this invention;

Fig. 2 is a fragmentary longitudinal sectional view through the lehrshown in Fig. l;

Fig. 3 is a horizontal sectional view through the lehr;

Fig, 4 is a transverse sectional view through the lehr;

Fig. 5 is a fragmentary sectional view taken substantially on the line5--5 of Fig. 3;

Fig. 6 is a fragmentary sectional view taken on the line 6-6 of Fig..3;

Fig. 7 is a perspective view of one of the tiles forming a part of theconstruction; and

Fig. 8 is a fragmentary perspective view of the floor of the lehr.

Before proceeding with a description of the lehr disclosed in thedrawings, it might be noted that the invention is directed generally tothe provision of a partition between the source of heat and the ware tobe treated, which partition is so constructed that the heat which passesto the ware will be 'accurately controlled and distributed. lA partitionconstructed in accordance with the teachings of this invention may beincorporated in a lehr fired or heated in any desired manner and thedetails of construction of the lehr which is about to be described, aretherefore not to be construed as definitive of the type of lehr withwhich the invention may be associated. In other words, while theinvention has been shown as being incorporated in a lehr having certaincharacteristics, it will become apparent as this description proceedsthat the invention may be incorporated in a lehr or annealing furnaceofpractically any character whatever.

Referring now particularly to the drawings wherein like referencecharacters designate corresponding parts throughout all views, there isdisclosed a lehr having an annealing chamber ill through which the upperreach of an endless conveyor il extends. The conveyor may convenientlybe of the open mesh type and its upper reach may be supported on rollersI2 carried by suitable angle beams I3 which extend longitudinally of theannealing chamber.

, The lower reach of the conveyor may be supported on rollers I4'carried by bearings secured to suitable depending supports l5, while atits ends the conveyor is mounted on suitable drums IB and il. driven inany desired manner, as for example by the belt I8 driven from a suitablesource of power i9. It will be understood that the conveyor and itsdriving and supporting means may be as above described or may be of anyother desired character insofar as the conveyor provides means forconveying ware to be treated through the annealing chamber.

'I'he annealing chamber is shown as surrounded by side Walls 20, a roof2l and a iioor 22. 'I'hese walls, roof and floor of the furnace may beof standard construction, they being preferably formed of brick work andrefractory, material, framed, braced and tied together in any desiredmanner. Likewise the roof of the lehr may be provided with pyrometerblocks 25 in accordance with the usual practice, While at its ends thelehr may be provided with vertical fiues 26 which communicate with theannealing chamber.

Spaced above the floor 22 of the annealing chamber is a horizontallydisposed partition or hearth designated generally lby the referencecharacter 30. This partition may be conveniently formed of tiles 3ihavingoffset edge portions 32 so that the edges of adjacent tiles willoverlap as illustrated in Figs. 4 and 5 of the drawings. At its edgesthe partition is supported at spaced points from the licor of theannealing chamber by suitable supports 33, while at spaced pointscentrally of the partition and preferably at the corner of four adjacenttiles, the partition is supported by suitable supports 34.

The spaced relation of the partition 30 vfrom the oor 22 of theannealing chamber provides a tunnel flue or fire box 40 which extendslongitudinally of the lehr from the inlet to the outlet The drums il maybe conveniently end thereof. The annealing chamber is defined at leastin part by the partition 30 which constitutes a surface or wall disposedbetween the annealing chamber and the re box 40. Fuel is supplied to thefire box by suitable burners illustrated diagrammatically in Fig. 3 anddesignated by the reference character 4l, there being preferably threeof these burners disposed on one side of the lehr and two on the otherside thereof. It will be obvious however, that the number andarrangement of the burners may be varied as desired insofar as thedesired amount of heat is supplied to the fire box or tunnel.

It will be noted that the longitudinal edges of the partition 30 arespaced from the inner faces of the side walls of the annealing chamberwhereby some of the heat from the tunnel flue may pass upwardly aroundthe side edges of the partition and into the annealing chamber I0. Alarge amount of the heat however passes through the partition and isradiated from the partition to the ware travelling through the annealingchamber on the conveyor I l. The present invention accordinglycontemplates the forming of the partition 30 of sections varying inthermal conductivity with the result that heat will be radiated invarying amounts from this partition.

Referring now more particularly to Fig. 3 of the drawings, the firstfour tiles are designated by the reference character 3l* and under theteachings of this invention these tiles are preferably formed of somematerial having a relatively low co-eillcient of thermal conductivitysuch, for example, as alundum. The next ten tiles are designated by thereference character Sib and these tiles are formed of a material havinga higher co-eflicient of thermal conductivity such, for example, ascarborundum. It might be noted that the thermal conductivity of thetiles of carborundum is about 1.5 times that of the tiles formed ofalundum.

'I'he next two tiles are designated by the reference character 3| andthese tiles are formed of some high temperature metal whose thermalconductivity is about ten times as great as that of the alundum. Thefinal tiles, designated by the reference character Sid may be formed ofcast iron or similar metal.

While it will be understood that the number and arrangement of the tilesmay be varied in any manner desired, and that while further thevmaterial of which these tiles are formed may also be varied, in theembodiment of the invention illustrated, the tiles having a relativelylow co-efiicient oi' thermal conductivity are disposed adjacent theentrance of the annealing chamber and thus immediately over that portionof the tunnel flue lll which is highly heated by the burners Il.Obviously the use of tiles formed of a material having a. lowco-eillcient of thermal conductivity is possible in this section of theannealing chamber by virtue of the high temperature of the tunnel flue Mat that point.

'I'he next tiles lib are formed of a material having a higher co-emcientof thermal conductivity so that in the construction illustrated, theware travelling through the lehr will be sub- Jected to the greatestheat adjacent the last burner Il. Since the heat is somewhat dispelledat points more remote from the burners, the higher thermal conductivityof the tiles Sie and 3|*i permits suilicient heat to pass from thesubjacent portion of the tunnel 4l to the ware.

Obviously, if it were desired to obtain a quick rise in temperature andthen a sudden drop. the

plates of the greatest thermal conductivity might be placed immediatelyover the burners and plates of lower conductivity placed over theremaining portion of the tunnel flue. In all cases, however, the tilesmay be so arranged as regards the co-eillcient of thermal conductivityof the material from which they are formed that any desired temperaturegradient may be obtained within the annealing chamber and this may beaccurately controlled without the use of complicated and expensivetemperature control mechanisms.

As previously mentioned, it will be apparent that the tunnel flue orfire box may be heated in the manner described or in any other desiredmanner. Additionally, the lehr itself may be formed in any desiredmanner and the desired circulation of the heating gases effected in anyof the usual ways. Under the teachings of this invention however, thereis associated with the annealing chamber a radiating means or partition,sections of which vary as regards their thermal conductivity with theresult that the heat to which the ware is subjected may be accuratelycontrolled. Throughout the specification and claims the term lehr"should be construed as meaning the complete construction which includesthe heating means, cooling means, if such are utilized, and the meansfor conveying the ware,.while the term annealing chamber should beconstrued as meaning the chamber formed within the lehr through whichthe ware to be annealed is conveyed.

While the invention has been described with some detail, it is to beunderstood that the description is for the purposes of illustration onlyand is not definitive of the limits of the inventive idea. The right isreserved to make such changes in the details of construction andarrangements of parts as will fall within the purview of the attachedclaims.

What I claim as my invention is:

l. In a lehr, an annealing chamber, a heat radiating partition extendinglongitudinally of said chamber and disposed horizontally thereof, a wareconveyor arranged to advance longitudinally of said chamber above saidpartition, and means including a fire box disposed below said partitionfor heating the underface thereof, said partition being formed of threesections, one adjacent the inlet end of the chamber, a secondonedisposed intermediately of the chamber, and a third section disposedadjacent the outlet end of the chamber, and the first section beingformed of a material of relatively low thermal conductivity, the secondsection being formed of a material having a thermal conductivity ofapproximately one and one-half times that of the first section, and thethird section being formed of a material having a thermal conductivityof approximately ten times that of the rst section.

3. In a lehr, an annealing chamber, means for heating said chamber, anda partition comprising a plurality of tiles arranged in edge to edgerelation and forming a wall of said chamber, said partition beingdisposed between the said heating means and the chamber, certain of saidtiles being formed from a material having a thermal conductivitydiffering from that of the material from which others of said tiles areformed to radiate more heat into the chamber from certain portions ofthe partition than is radiated into the chamber from other portions ofthe partition.

4. In a lehr, an annealing chamber, a heat 15 radiating partitionextending longitudinally of said chamber and disposed horizontallythereof, said partition forming the bottom Wall of said chamber, a Wareconveyor arranged to be advanced longitudinally over said partition, andmeans positioned below said partition for heating the under facethereof, said partition comprising a plurality of tiles arranged in edgeto edge relation, certain of said tiles being formed from materialhaving a thermal conductivity differing from that of the material fromwhich others of said tiles are formed to radiate more heat into thechamber from certain portions of the partition than is radiated `intothe chamber from other portions of the partition.

JOSEPH F. GREENE.

